问题 单项选择题

洗脱液的质量控制下列哪种说法是错误

A.99Mo可增加对患者的辐射吸收剂量、影响显像质量,其含量应低于0.1%
B.载体99Tc可由99Mo和99Tc衰变产生,其含量随淋洗时间间隔和洗脱液放置时间增长而增高,故应多延长淋洗时间
C.Al可影响放射性药物的标记和体内分布,如可使某些放射性药物在肝脾中浓聚,Al含量应低于10μg/ml
D.99mTc增长到最大值的时间为22.8小时
E.99Mo含量可用740~780keV能谱分析测定

答案

参考答案:B

解析:淋洗时间间隔和洗脱液放置时间增长,由于射线对水的辐射分解产生的过氧化物游离基含量还会增加,影响洗脱液质量,故一般淋洗时间间隔为24小时。

单项选择题
阅读理解

B

Chinese are very generous when it comes to educating their children. Not caring about the money, parents often send their children to the best schools or even abroad to England, the United States and Australia. They also want their children to take extra-course activities where they will either learn a musical instrument or ballet, or other classes which will give them a head in life. The Chinese believe that the more expensive an education is, the better it is. So parents will spend an unreasonable amount of money on education. Even poor couples will buy a computer for their son or daughter.

However, what most parents fail to see is that the best early education they can give their children is usually very cheap.

Parents can see that their children are very skilled in some areas while poor in others. What most parents fail to realize though, is that today’s children lack self-respect and self-confidence.

The problem is that parents are only educating their children on how to take multiple-choice tests and how to study well, but parents are not teaching them the most important skills that they need to be confident, happy and clever.

Parents can achieve this by teaching practical skills like cooking, sewing and doing other housework.

Teaching a child to cook will improve many of the skills that he will need later in life. Cooking demands patience and time. It is an enjoyable but difficult experience. A good cook always tries to improve his cooking, so he will learn to work hard and gradually finish his job successfully. His result, a well-cooked dinner, will give him much satisfaction and lots of self-confidence.

Some old machines, such as a broken radio or TV set that you give your child to play with will make him curious and arouse his interest. He will spend hours looking at them, trying to fix them; your child might become an engineer when he grows up. These activities are not merely teaching a child to read a book, but rather to think, to use his mind. And that is more important.

61.Parents in China, according to this passage, ____________.

A.are too strict with their children

B.are too rich to educate their children

C.have some problems in educating their children correctly

D.are too poor to educate their children

62.The writer of this passage does not seem to be satisfied with_______.

A.  the parents’ ideas of educating their children

B.  the education system

C.  children’s skills

D.  children’s hobbies

63.Doing some cooking at home helps children_________.

A.  learn how to serve their parents

B.  learn how to become strong and fat

C.  benefit from it and prepare themselves for the future

D.  make their parents believe that they are clever